It really depends on how thickly you have sprayed it and the ambient temperature. If the coat is thin then you can assembly pretty quickly. If you have put it on too thick it will take much longer. I usually wait overnight, but sometimes I get impatient and wait only an hour. Good painters are faster assemblers too I guess. :D
 
I usually wait two days before I dimple, but have not had any problems dimpling the next day if in a hurry.